Where Should We Build Utility-Scale Solar Power Plants?

The push to create big, utility-scale solar projects is having a moment. Solar panels are cheap and getting cheaper. And if construction begins on solar projects before the end of this year, developers receive a valuable tax credit.

It's accepted fact that solar projects will continue to multiply and will one day be cost-competitive with other forms of energy. But it’s unclear where all of the solar capacity will be built. Large-scale solar projects take up expansive tracts of land, and certain features make some areas more attractive than others.

Obviously enough, the land needs to be sunny so the panels can harvest the greatest possible amount of solar energy. The process is smoother if the land is flat. And the energy needs to travel to its destination, so land near existing or planned transmission lines also has an advantage.

The federal government began working a couple of years back to fast-track solar projects on public land. But officials discovered a couple of features that can make land unattractive for solar development. Most of the utility-scale solar projects that exist or are in development are in the desert of the Southwest. Most people don’t think of those areas as valuable land, but some of the proposed solar sites have cultural significance. The Native American group La Cuna de Aztlan Sacred Sites Protection Circle sued the Department of the Interior over plans to build projects near or over geoglyphs—gigantic designs etched into the desert generations ago. And solar development threatens desert species like the sage grouse, the desert tortoise, and the burrowing owl. Some environmental groups have argued that digging up the desert’s scrubby plant life will have a carbon impact similar to cutting down a forest.

So where will large-scale solar projects go? Here are a few of the more palatable options:

Solar Energy Zones. After running into obstacles with its fast-tracked projects, the Department of the Interior re-evaluated its solar plans. Last month, the department released a revised impact statement that highlighted about 285,000 acres split among 17 sites near transmission lines with minimal environmental or cultural conflicts. The department estimates that in the next two decades, solar developers will need 214,000 acres of public land, so the current zones could offer opportunities for quite a while.

Contaminated land. The interior department is also granting permission to develop land once used for agriculture—tracts that are not pristine desert. Meanwhile, some solar developers are exploring using land that’s already damaged and unfit for agricultural, residential, or commercial development—like Superfund sites, landfills, or brownfields ruined by industrial processes or dumping.

Offshore. The federal government has been investigating the possibility of installing solar farms offshore, but this idea comes with its own unique challenges. Solar farms could interfere with commercial or recreational boat traffic. Large expanses of solar panels or concentrating solar projects would shade the ocean beneath, changing and possibly harming the ecosystems below. There’s also the problem of what the government refers to as “avian perching opportunities,” which could mean off-shore panels would need more frequent cleanings than onshore installments.